Process and apparatus for cracking hydrocarbon oils



G. EGLOFF 1,965,335 PROCESS AND APPARATUS FOR CRACKING HYDROCARBON OILS Ju y 3, 1934,

Original Filed June 21, 1 920 Patented July 3, 1934 PROCESS AND APPARATUS FOR CRACKING i HYDROCARBON OILS Gustav Egloff, Chicago,

111., assignor to Universal Oil Products Company, Chicago, Il1., a. corporation of South Dako Continuation of application Serial No. 390,369,

June 21, 1920. This application August 2 1929, Serial No. 388,604

8 Claims.

This application is a continuation of my copending application Serial No. 390,369, filed June 21, 1920 for Process and apparatus for cracking hydrocarbon oil.

This invention relates more particularly to a process for cracking oils for the production of gasoline or gasoline like bodies from oils which in themselves contain no gasoline.

Among the objects of the invention are to provide a continuous process in which the reflux condensate is subjected to a higher temperature than that to which it was originally subjected, this condensate being more refractory in character than was the original oil; to provide a process in which the fresh oil to be treated may be fed directly into the dephlegmator and passed into the corresponding still counter-current to the ascending vapors; to provide a process in which the overflow oil from one still passes to the succeeding still of the battery; to provide a process in which the final condensate from any given still is or may be separately collected; to provide a novel form of apparatus for carrying out this process and in general to provide improvements of the character referred to.

In the drawing, 1 designates the supply pump for the raw oil which is connected to a source of supply through pipe 1a controlled by valve 1b. The raw oil is delivered through pipe 2 controlled by valve 3 to the battery of the stills. The stills 4, 5, 6, 7 and 8 in the present instance are shown as of the horizontal shell type, although different types of stills such as vertical stills, water tube boilers or horizontal tube boilers may be used. These stills are respectively mounted in the furnaces 9, 10, 11, 12 and 13 and gas is supplied to them through gas line 14 having gas burners 15.

The vapors pass out of the respective stills through the vapor lines 16, the upper ends of which are connected to dephlegmators 17, each provided with a plurality of baflle members 17a. The vapors which are not condensed in the dephlegmator pass out through the line 18 then through water condenser coil 19 and thence into the respective receivers 20. Each receiver is provided with liquid draw-off 21 and control throttle valve 22. The lines 21 may lead to a common storage tank (not shown). Each receiver is provided with a pressure gauge 26 and gas outlet 27,

' the latter being controlled by throttle valve 27a. That portion of the vapors which condense in the dephlegmator is conveyed by lines 25 welded as shown at 24 to the vapor lines 16 to the succeeding still of the battery as clearly appears in the drawing. The raw oil can be fed into the upper end of the respective dephlegmators, if desired, through the line 28, manifold line 30 and branches 31. These branches 31 communicate with the upper end of each dephlegmator and are provided with control valves 32. Likewise a throttle valve 29 may be interposed in the line 28. The liquid overflows to the respective stills of the battery through the overflow pipes 33, provided with the upright extensions 34 and 34a. The liquid level of the oil in the stills is shown in the dotted lines in the drawing. The last still of the battery is provided with drawoff line 35 controlled by throttle valve 36. Throttle valve 3'7 may also be interposed in the lines 25.

The following illustration of the operation of the process may be given: The battery of stills may be charged with Kansas gas oil of 32 Baum gravity to the level of the overflow pipes in the stills. The valves 27a on the receivers are closed and the valves 37 on the reflux condensate pipes 25 are open. The pump is shut down and valves 3 and 29 are closed. The burners 15 are lighted and the oil heated so that a pressure of 90 lbs. is generated on the entire battery of stills. When the pressure distillation begins, the pressure distillate is drawn through the lines 21 and the valves 22 and 27a are operated to control the pressure. After the stills are operating on pressure, the pump can start to continuously feed fresh oil into the apparatus and the valves 3 and 29 are opened.

The extent to which they are opened will control the amount of oil fed through the line 28. At this time, of course, the valves 32 were opened as well as the valves 37. By reason of the baiile members 2411 inserted in the line 16, the reflux condensate and any fresh oil charged into the upper end of the dephlegmator will flow through the line 25 into the next still of the battery. A pressure of 90 to pounds may be maintained on the system by suitably regulating the valves shown. If desired, a difierent pressure may be maintained between the dephlegmator and condenser coils 19 by means of the valves 18a shown in the drawing. The oil temperature in the stills may, for example, vary from 700 F. in still 4, 720 F. in still 5, 740 F. in still 6, 760 F. in still '7, 780 F. in still 8. This process should produce from the gas oil referred to, 50% of pressure distillate of 51 Baum gravity or upon the basis of gas oil used, 35% or more of 58 Baum gravity gasoline.

Having thus described the invention, what I claim is:

1. A cracking process which comprises subjecting hydrocarbon oil to cracking conditions of same in direct contact with heavy oil to be cracked, introducing the resultant mixture of unvaporized heavy oil and reflux condensate to a second cracking zone maintained at higher cracking temperature than said first zone, removing vapors from said second zone and dephlegmating the same in direct contact with additional heavy oil to be cracked thereby forming another mixture of unvaporized heavy oil and reflux condensate, and cracking the last-mentioned mixture in a cracking zone maintained at higher temperature than said first zone.

2. A cracking process which comprises subjecting hydrocarbon oil to cracking conditions of temperature and pressure in a first cracking zone, removing evolved vapors and dephlegmating the same in direct contact with heavy oil to be cracked, introducing the resultant mixture of unvaporized heavy oil and reflux condensate to a second cracking zone maintained at higher crack- ,ing temperature than said first zone, removing vapors from said second zone and dephlegmating the same in direct contact with additional heavy oil to be cracked, thereby forming another mixture of unvaporized heavy oil and reflux condensate, supplying the last-mentioned mixture to a third cracking zone maintained at higher temperature than said second zone and cracking the same therein at the higher temperature prevailing in the third zone.

3. A cracking process which comprises subjecting hydrocarbon oil to cracking conditions of temperature and pressure in a first cracking zone, removing evolved vapors and dephlegmating the same in direct contact with heavy oil to be cracked, introducing the resultant mixture of unvaporized heavy oil and reflux condensate to a second cracking zone maintained at higher cracking temperature than said first zone, removing unvaporized oil from said first zone and introducing the same to said second zone, removing vapors from said second zone and dephlegmating the same in direct contact with additional heavy oil to be cracked, thereby forming another mixture of unvaporized heavy oil and reflux condensate, and cracking the last-mentioned mixture in a cracking zone maintained at higher temperature than said first zone.

4:. A cracking process which comprises subjecting hydrocarbon oil to cracking conditions of temperature and pressure in a first cracking zone, removing evolved vapors and dephlegmating the same in direct contact with heavy oil to be cracked, introducing the resultant mixture of unvaporized heavy oil and refiux condensate to a second cracking zone maintained at higher cracking temperature than said first zone, removing vapors from said second zone and dephlegmating the same in direct contact with additional heavy oil to be cracked thereby forming another mixture of unvaporized heavy oil and reflux condensate, supplying the last-mentioned mixture to a third cracking zone maintained at higher temperature than said second zone and cracking the same therein at the higher temperature prevailing in the third zone, removing unvaporized oil from said first zone and introducing the same to said second zone, and similarly removing unvaporized oil from said second zone and introducing the same to said third zone.

5. An oil cracking apparatus comprising a series of stills, means for heating the stills, means for introducing oil to be cracked into the first still of the series, a dephlegmator connected to each still in the series, means for introducing oil to be cracked into each dephlegmator and into direct contact With the vapors therein, and means for delivering the unvaporized oil to be cracked and admixed refiux condensate from the dephlegmator connected to each still, except the last, of the series to the next succeeding still in the series.

6. An oil cracking apparatus comprising a series or" stills, means for heating the stills, means for introducing oil to cracked into the first still of the series, means for delivering unvaporized oil from each still, except the last of the series, to the next succeeding still in the series, a dephlegmator connected to each still in the series, means for introducing oil to be cracked into each dephlegmator and into direct contact with the vapors therein, and means for delivering the unvaporized oil to be cracked and admixed reflux condensate from the dephlegmator connected to each still, except the last, of the series to the next succeeding still in the series.

7. An oil cracking apparatus comprising a series of stills, means for heating the stills, a charging oil pump, means for delivering charging oil from the pump to the first still of the series, a dephlegmator connected to each still of the series, means for passing charging oil from the pump into each dephlegmator and into direct contact with the vapors therein, and means for delivering unvaporized charging oil and admixed reflux condensate from the dephlegmator connected to each still, except the last, of the series to the next succeeding still in the series.

8. An oil cracking apparatus comprising a series of stills, means for heating the stills, a charging oil pump, means for delivering char ing oil from the pump to the first still of the series, means for delivering unvaporized oil from each still, except the last of the series, to the next succeeding still in the series, a dephlegmator connected to each still of the series, means for passing chargl ing oil from the pump into each dephlegmator and into direct contact With the vapors therein, and means for delivering unvaporized charging oil and admixed refiux condensate from the dephlegmator connected to each still, except the last, of the series to the next succeeding still in the series.

GUSTAV EGLOFF. 

